Bottom automatic limit-stop for flunger-elevators.



.A F. C. FURL'OW.

BOTTOM AUTOMATIC LIMIT STOP FOR PLUNGER ELBVATORS.

.I APPLIOATIONTILBD DEG. 7, 1905. 1,011,338.

j s E Itfventr: f (3% COLUMBIA PLANOGRAPH C0.. WASHlNnToN. D., C.

Patented Dec.12, 1911.

F. C. FURLOW. 4 i BOTTOM AUTOMATIC LIMITl STOP FOR PLUNGER ELEVATORS. i APPL1oATIoN1-1L3D-DBo-7,1905. 1,01 1,338, Patented Dec. 12,1911.

z SHEETS-SHEET 2. l

COLUMBIA PLANOGRAPM C0.,wAsn|NGToN u c UNITED STATES PATENT OFFICE.

. FLOYD C. lFUIR'LOW, OIE" MONTCLAIR, NEW JERSEY, ASSIGNOR TO OTIS ELEVATOR COIVL PANY, 0F JERSEY CITY, NEW JERSEY, A CORPORATION OF .NEW JERSEY.

EOT-TOM AUTOMATIC LIMIT-STOP FOR. PLUNGER-EI'JEVATORS.

To all whom it mag/'concerns Y Be it known that I, FLOYD C. F URLoW, a citizen of the AUnited States, residing in the city of Montclair, in the county of Essex and State of New Jersey, have'invented a new and useful Improvement in Bottom Automatic'Limit-Stops for Plunger-Elevators, of which the following is a specilication.

My invention relates to automatic limit stops for plunger elevators, and one of its objects is the provision of simple and eilicient means for gradually andautomatically stopping an elevator car at the limits of its travel without shock or jar.

More particularly it is the object of the present invention to provide means co-acting with the bottom of the plunger to bring the car gradually to rest at the lower limit of its travel.

' Other objects of the present invention will appear hereinafter, the novel combinations of elements being pointed out in the claims.

In the accompanying drawings, Figure 1 represents in elevation, a simple plunger elevator with my invention applied thereto; Fig. 2 is an elevational sectional view illustrating the details of one embodiment of my invention; Fig. 3 is a cross-sectional plan view of Fig. 2, taken on the line w-a, and Figs. 4, 5. 6, and 7 illustrate modifications.

It has been discoveredv that with plunger i; cause injury to the passengers, or to any part of the elevatorapparatus. A stop of this kind is particularly desirable as the car approaches the bottom of the run. for in addition to the live load in the car, the necessary underbalance for stopping the elevator on its up motiony must be resisted and the inertia of the moving parts overcome, so as to bring the car gradually to rest.

I-have herein disclosed certain apparat-us to illustrate the principles of my invention` but I do not desire to be limited or restricted to the precise constructions shown. Obviously, various changes in the details and arrangement of parts could be made by persons skilled in the art without departing from the spirit and scope ofvmy invention.

In Fig. 1, I have illustrated a simple form Specification of Letters Patent.

Patented Dec. 12, 1911.

Application filed December 7, 1905. Serial No. 290,716.

of plunger elevator to illustrate one application ofmy invention. The elevator apparatus may be any other type desired. In this instance, a car C is shown connected by means of the counterweight rope R to the counterweight W. The rope R passes around the sheave S mounted on the over-head beam B. Connected to the bottom of the car is a plunger P which is adaptedto be received by the standard cylinder 12 sunk into the earth and having only its upper portion or head 11 exposed in the p it 13. For controlling the How of motor-fluid to and from the cylinder 12, a change valve 7 may be employed which is provided with supply and exhaust ports 8 and 9 and connected to the Lcylinder head y11 by means of the pipe 10.

Any other desirable means for operating the change valve may be used, that here shown comprising an operating lever L in the car for actuating the operating rope 1, the upper ends of which are attached to the over-head beam B yat 2 and 3, and the lower end of which is passed one or more times around the drum D. This drum when rotated actuates the pinion 4 carried thereby. thus causing the valve stem 6 to be moved in the desired direction, since the latter is connected to the rack 5 which is in mesh with said pinion 4.

At the extreme lower end of the cylinder 12 is inserted a sleeve 13 composed of suitable material, such as brass. mav be cup-shaped as shown, and the lower end of the cylinder 12 shrunk over the same, or said cylinder 12 mav be provided with a bottom of its own and the sleeve without the bottom inserted within the cylinder 12 and allowed to rest on the cvlinder bottom. The upper portion of the sleeve is cut away at 14, so that there will be a gradual flaring between the cylinder 12k above the sleeve 13 and the portion of the sleeve below said cutaway portion 14. The sleeve 13 may be of anv desired thickness, but its internal diameter 'should be somewhat larger than the external diameter of the plunger P. kThe 'sleeve may be integral with the cylinder 12,

if desired.

They plunger P mav be hollow. as shown. Vor it may be solid. In any event, it should have a real bottom at'15. which in this case is shown as a partition. Immediately below This sleevethis partition, as shown, is a series of holes or perforations 16 of any desired size, in this instance circumferentially arranged. At a suitable distance below this series of holes is an additional partition 17 to form a false bottom provided with a central opening 18. The upper side of the partition 17 may be flat, but the under side of said partition should taper from the interior wall of the plunger P to the central opening 18, so that the ball 19 confined within the chamber below partition 17 will roll to said opening 18 and close the same when desired. The plunger P extends a convenient distance below the partition 17 and is provided with an additional false bottoni 22 which is preferably a disk suitably secured to the lower end of the plunger P, which disk is provided with a plurality of perforations or apertures 21.. The bottom 22 may be omitted if desired, and the lower end of the downwardly-extending portion 24 left entirely7 open, or the downwardly-extending portion may be provided with a series of apertures as shown in Figs. 4 and 6 or with tapering slots as shown in Fig. 7. In such case, the operating fluid may enter the apertures 16 and also the apertures or slots at the lower end of the portion 24 in order to exert a pressure on the bottom 15 of the plunger P.

It will be seen that in Fig. 2, an appreciable space occurs between the sleeve 13 and the portion 24 when the plunger P is at the lowermost limit of its travel. Vhen the plunger P is on the bottom of the cylinder 12, the lower end of the portion 24 as shown in Fig. -2 will be almost entirely closed. It is therefore preferable to provide the openings 16 at such a distance above the bottom 22, that said openings will occupy a position at or a little above the flared or bell-mouthed portion 14 of the sleeve 13. This would allow the car to be started upwardly in a minimum space of time. If the lower end of the portion 24 is provided with perforations as 25 of Figs. 4 and 6, or with the slots 27 of Fig. 7, the pressure uid may also act upwardly through the lower portion 24 and the hole 18.

The ball 19 should be supported preferably a short distance below the opening 18. I have in this instance shown a spider composed of inwardly-projecting inclined planes 20 secured to the interior wall of the eX- tended portion 24 of the plunger P. This spider is so constructed that when the ball falls -it will be directed to a position immediately below the opening 18.

In Fig. 4, I have shown a modification, in that the lower portion 24 lits more closely within the sleeve 13 when the plunger P is resting on the bottom of the cylinder 12; and furthermore, that the lower portion 24 is provided with a plurality of apertures Fig. 6 is a view similar to Fig. 4, but

showing a weighted valve 19 substituted for the ball check-valve shown in Figs. 2 and 4.

In Fig. 5, I have shown a sleeve 13 provided with a pluralityof holes for a purpose hereinafter specified.

In order to show how the means for gradually retarding the downward movement of the plunger P as the same approaches the lower limit of its travel, may be modified, I have substituted slots 25 in Fig. 7 for the perforations 25 of Figs. 4 and 6.

The operation of my invention is as follows: As the elevator car descends and approaches the lower limit of its travel, the lower portion 24 of the plunger P will enter the sleeve 13 or reduced portion of the bottom of the cylinder 12. Vhile the elevator car and plunger descend from their upper limit of travel, the ball 19 may or may not close the opening 18, depending on the total load operating to move the plunger P downwardly, or upon the rate of flow of the fluid from the cylinder 12. When the extreme lower end of the plunger P enters the bellmouth 14, the space through which the water or operating fluid can flow from beneath the plunger is gradually reduced. The plunger can descend only so fast as the water can be forced out, and therefore the car will come gradually to rest. The excess pressure on the fluid beneath the plunger P as the latter enters the flared portion 14 will operate to force the ball 19 upwardly to close the opening 18 and therefore prevent the motor fluid from discharging in this direction, that is, through the opening 18 and the circumferential series of holes 16. The effective bottom of the plunger P instead of being the partition 15 will now be at the false bottom 17 or the effective bottom may be considered as being shifted to the false bot-- tom 22 inasmuch as the fluid within the eX- tension 24 is confined when the check valve is closed. hen the plunger P reaches its lowermost position and the elevator has come to rest without shock or jar, the ball 19 will fall back to its original position in the center of the spider composed of inclined planes 20. As shown in Fig. 2, the fluid can not enter through the perforations 0r apertures 21 to any operative extent, since these perforations are closed by the bottom of the cylinder 12 or the bottom of the sleeve 13, depending upon the particular construction of the cylinder and sleeve selected. If the portion 24 is provided with the apertures 25 of Figs. 4 and 6 or with the slots 25 of Fig. 7, the operating fluid may act through the same to assist in transmitting fluid pressure to the bottom 15. It is furthermore evident that when it is desired to move the car upwardly from its lowermost position, within a minimum space of time, the pressure Yshould be exerted 19, in reality constitute a check-valve; but

a flap valve, or a weighted puppet valve or any other suitable valve opening downwardly may be used in place of the ballcheck-valve if desired, provided the construction is substantially the same as herein disclosed and accomplishes substantially the same results. I have illustrated one modified form of check valve in Figs. 6 and 7. It will be seen that the valve 19 is weighted at 27 in order to hold the same in open position, but the movement of this valve '19 in its downward direction is limited by the projection 28 striking against the bottom of the partition 17 The valve 19 is preferably hinged on the lower side of the partition 17 immediately below an edge of the opening 18. When the modification shown in Fig. 4 is used and the elevator approaches the lower limit of its travel, the fiuid is not immediately confined within the lower portion 24 of the plunger P, but can escape through the openings 25. The stopping of the car at the lower limit of its travel can be graduated to Vany extent by lengthening or shortening the sleeve 13, or by suitably arranging the number and position of the holes -25. When the extreme lower end of the plunger P first enters the bell-mouth 14, the fluid is forced mostly through the openings 25 which are closed one after another, or step-by-step, until the only means of escape for the Huid is between the portion 24 and the sleeve 13. This space may be varied as desired. The operation of the const-ruction shown in Figs. 6 and 7 is substantially the same as that described withreference to Fig. 4. In any of these constructions, if desired, the maximum number of perforations may be placed at the top instead of the bottom as shown.

In Fig. 5, I have shown an annular hollow sleeve provided with perforations at its upper portion. VIn this case,.when the extreme lower end of the plunger P enters the bell-mout-h 14, the liuid may circulate'more or less within the annular sleeve 13, but this circulation is gradually cut off as the portion 24 passes the mouth 14, until the only means of escape for the fluid is within the annular space between the port-ion 24 and the lower portion of the sleeve 13. rIhis space may obviously be varied as desired. Figs. 4, 6 and 7 show clearly how the operating pressure may bey transmitted through the openings 16 to the bottom 15 of the plunger, yin order to c move the car quickly in an upward4 direction from its lowermost limit of travel. v Having thus described my invention,what

plunger, and a communicating passage between the exterior lateral and bottom surfaces of the plunger controlled by said valve.

2. In an elevator, the combination with a cylinder having a portion of reduced diameter, of a plunger, a normally open check valve at or near the lower end of said plunger, and a communicating passage controlled by said valve between the lateral and bottom surfaces ofthe plunger.

3. In `an elevator, the combination with a cylinder having its lower end of reduced diameter, of a plunger, a valve normally open and opening downwardly and connected to said plunger, and a passage between the lateral and vbottom surfaces of the plunger, saidl passage being controlled by said valve.

4. In an elevator, the combination with a cylinder having its lower portion of reduced diameter, of a hollow plunger, a normally open valve at or near the lower end of the plunger and opening downwardly, and a communicating passage between the'lateral and bottom surfaces of the plunger controlled by said valve. v

5. In an elevator, the combination with a cylinder having a portion of reduced diameter, of a hollow plunger, a normally open check valve at or near the lower end of the plunger and opening downwardly, and a passage between the lateral and end surfaces of the plunger controlled by said valve.

6. In an elevator, the combination with a car, of a closed hollow plunger therefor, a cylinder for said plunger and having its lower end of reduced diameter, means for controlling the flow of motor-fluid to and from said cylinder, a normally open valve at or near the bottom of said plunger,` and a communicating passage between the exterior lateral and bottom Vsurfaces of the plungerl controlled bysaid valve. .c

7. The combinationv with fa movable body, of a plunger connected thereto, a cylinder. for receiving said plunger, the lower portion of said cylinder being of reduced diameter, means for controlling the flow of motor-fluid to and from saidl cylinder, and means for lowering the effective bottom of said plunger to effect a retardation of movement of the latter when entering said reduced portion of the cylinder.

8. The combination with a car and a plunger, of a cylinder' for receiving said plunger, means for controlling thecfiow ofmotor-fluid to and from said cylinder, and

means co-acting with the lower port-ion of said plunger for lowering the effective bottom of the plunger and for effecting a gradual stopping of said car at the lower limit of its travel.

9. The combination with a car and its plunger, of a cylinder for receiving said plunger, means for controlling the application of fluid-pressure to said plunger to operate the car, an extension carried by the plunger and forming a continuation thereof, a passageway extending through said extension, a check valve controlling said passageway, and a flared sleeve at or near the lower end of said cylinder for effecting the operation of said valve and the consequent lower ing of effective bottom of t-he plunger to cause a gradual retardation of said car to stop the same at the lower limit of its travel with minimum shock or ar.

10. In a hydraulic elevator, the combination with a car and its plunger, of a cylinder for said plunger, means for controlling the flow of motor-fluid to and from said cylinder, a shifting bottom for said plunger, and means co-acting with said shifting bottom for bringing the car gradually to rest at the lower limit of its travel. p

1l. In a hydraulic elevator, the combination with a car, of moving means for said car comprising a plunger, av false bottom for said plunger, means for effectively closing said bottom, and means co-acting with said bottom when it is closed to gradually retard the movement of said car when approaching the lower limit of its travel.

12. In a hydraulic elevator, the combination with a car, of moving means for said car comprising a plunger having a real bottom and a false bottom, a valve for effecting the closure of said false bottom, and means co-acting with said false bottom when thus closed to gradually retard the movement of said car as it approaches the lower limit of its travel.

13. In a hydraulic elevator, the combination with a car, of moving means therefor comprising a plunger, a partition forming a false. bottom in a downwardly-extending portion of said plunger said partition having a central opening and a series of openings being provided in said extended portion between the bottom of the plunger and said partition, means for automatically closing the central aperture in said partition, and means co-acting with said closing-means for effecting the gradual retardation of the car as the same approaches the lower limitof its travel.

14. In a hydraulic elevator, the combination with a car, of moving means therefor comprising a plunger and a cylinder for receiving said plunger, a partition forming a false bottom in a downwardly-extending portion of said plunger said partition having an opening and there being one or more openings in said extended portion between the real bottom of the plunger and said partition, means for closing the opening in said partition, and means connected to the lower` portion of said cylinder and co-acting with said closing means for gradually retarding theI movement of the car as the same approaches the lower limit of its travel.

15. In a hydraulic elevator, the combination with a car, of a plunger, a cylinder for said plunger, motor-fluid controlling means to start and stop the car, a partition forming a false bottom in a downwardly-extend' ing portion of said plunger, said partition having an opening therethrough and there being a series of openings through said downwardly-extending portion beneath the bottom of said plunger, a spider, a perforated disk at the lower end of said downwardly-extending port-ion, a ball conned between the said partition and said spider and adapted to close the opening in said partition, and a sleeve flared at its upper portion and connected to the bottom of the cylinder and having an internal diameter less than the internal diameter of the cylinder.

16. In a plunger elevator, in combination, a plunger having a. valve at its lower end normally open and opening downwardly, the plunger being formed with an aperture extending through a portion thereof and controlled by the valve, a plunger cylinder, and means for retarding the plunger.

17. In a plunger elevator, the combination of a plunger having a real and a false bottom, a normally open valve for said false bottom, and a cylinder constructed and are ranged to cooperate with the plunger.

18. In a plunger elevator, the combination of a plunger having a real bottom and a false bottom, a normally open check valve for closing said false bottom, and a cylinder constructed and arranged to cooperate with the plunger.

19. In a plunger elevator, the combination of a plunger having an extended portion at its lower end, a ball supporting device in said extended portion, an apertured partition in said extended portion, a ball between said supporting device and said partition for closing said partition and preventing motor-fluid from flowing through said partition, said extended portion being formed with one or more holes therethrough above said partition, and a cylinder constructed and arranged to coperate with the plunger.

20. A hydraulic plunger having an extended portion at its lower end, a ball supporting device in said extended portion, an apertured partition in said extended portion, and a ball between said supporting device and said partition for closing said partition and preventing motor fluid from flowing through said partition and one or more holes through said extended portion Lon-,se

above said partition, and a sleeve adapted tof be inserted at or near one end of the cylinder.

2l. In an elevator, the combination with a plunger having a closed bottom, of a cyl# inder having a reduced diameter near its bottom, means for automatically forming a lower bottom and arresting the said closed bottom of the plunger a short distance above the bottom of the cylinder.

22. In an elevator, the combination with a plunger, of a cylinder, and a hollow perforated sleeve at or near the lower portion of the cylinder' and co-acting with the lower end of the plunger to bring the latter to a stop gradually.

23. In an elevator, the combination with a plunger, of means for receiving said plunger, a bell-mouthed sleeve in the lower portion of the receiving-means, an eXtension from the lower end of the plunger provided with lateral passages and being open at its lower end, and means within said eX- tension for lowering the effective bottom of the plunger while said extension enters said Copies of this patent may bey obtained for ve cents each, by addressing the Commissioner of Patents, n

nected to the upper end of the plunger,

of a cylinder, means for controlling the flow of motor-Huid to and from said cylinder in the operation of the load-carrying device and the plunger, and a flared or bellmouthed, perforated hollow sleeve connected to the lower portion of said cylinder.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

FLOYD o. runnow.

' Witnesses: c y

W. H. BRADY, A. M. ZABRISKIE.

Washington, ID. C. 

